This is an automated email from the ASF dual-hosted git repository. ztao1987 pushed a commit to branch ztao in repository https://gitbox.apache.org/repos/asf/hawq.git
commit d5caf58d746145a00fdfc0ac7045f7169dce1911 Author: ztao1987 <zhenglin.ta...@gmail.com> AuthorDate: Mon Jan 3 17:02:52 2022 +0800 HAWQ-1824. Fix infinite loop problem of regex match function --- src/backend/regex/regc_nfa.c | 2493 ++++++++++++++++++++---------------------- src/backend/regex/regcomp.c | 12 +- 2 files changed, 1190 insertions(+), 1315 deletions(-) diff --git a/src/backend/regex/regc_nfa.c b/src/backend/regex/regc_nfa.c index ef56630..3d7b3bb 100644 --- a/src/backend/regex/regc_nfa.c +++ b/src/backend/regex/regc_nfa.c @@ -28,7 +28,8 @@ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * - * $PostgreSQL: pgsql/src/backend/regex/regc_nfa.c,v 1.7 2009/06/11 14:49:01 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/regex/regc_nfa.c,v 1.7 2009/06/11 14:49:01 + * momjian Exp $ * * * One or two things that technically ought to be in here @@ -36,452 +37,416 @@ * the color chains. */ -#define NISERR() VISERR(nfa->v) -#define NERR(e) VERR(nfa->v, (e)) - +#define NISERR() VISERR(nfa->v) +#define NERR(e) VERR(nfa->v, (e)) /* * newnfa - set up an NFA */ -static struct nfa * /* the NFA, or NULL */ -newnfa(struct vars * v, - struct colormap * cm, - struct nfa * parent) /* NULL if primary NFA */ +static struct nfa * /* the NFA, or NULL */ +newnfa(struct vars *v, struct colormap *cm, + struct nfa *parent) /* NULL if primary NFA */ { - struct nfa *nfa; - - nfa = (struct nfa *) MALLOC(sizeof(struct nfa)); - if (nfa == NULL) - return NULL; - - nfa->states = NULL; - nfa->slast = NULL; - nfa->free = NULL; - nfa->nstates = 0; - nfa->cm = cm; - nfa->v = v; - nfa->size = 0; - nfa->bos[0] = nfa->bos[1] = COLORLESS; - nfa->eos[0] = nfa->eos[1] = COLORLESS; - nfa->parent = parent; /* Precedes newfstate so parent is valid. */ - nfa->post = newfstate(nfa, '@'); /* number 0 */ - nfa->pre = newfstate(nfa, '>'); /* number 1 */ - - nfa->init = newstate(nfa); /* may become invalid later */ - nfa->final = newstate(nfa); - if (ISERR()) - { - freenfa(nfa); - return NULL; - } - rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->pre, nfa->init); - newarc(nfa, '^', 1, nfa->pre, nfa->init); - newarc(nfa, '^', 0, nfa->pre, nfa->init); - rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->final, nfa->post); - newarc(nfa, '$', 1, nfa->final, nfa->post); - newarc(nfa, '$', 0, nfa->final, nfa->post); - - if (ISERR()) - { - freenfa(nfa); - return NULL; - } - return nfa; + struct nfa *nfa; + + nfa = (struct nfa *)MALLOC(sizeof(struct nfa)); + if (nfa == NULL) return NULL; + + nfa->states = NULL; + nfa->slast = NULL; + nfa->free = NULL; + nfa->nstates = 0; + nfa->cm = cm; + nfa->v = v; + nfa->size = 0; + nfa->bos[0] = nfa->bos[1] = COLORLESS; + nfa->eos[0] = nfa->eos[1] = COLORLESS; + nfa->parent = parent; /* Precedes newfstate so parent is valid. */ + nfa->post = newfstate(nfa, '@'); /* number 0 */ + nfa->pre = newfstate(nfa, '>'); /* number 1 */ + + nfa->init = newstate(nfa); /* may become invalid later */ + nfa->final = newstate(nfa); + if (ISERR()) { + freenfa(nfa); + return NULL; + } + rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->pre, nfa->init); + newarc(nfa, '^', 1, nfa->pre, nfa->init); + newarc(nfa, '^', 0, nfa->pre, nfa->init); + rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->final, nfa->post); + newarc(nfa, '$', 1, nfa->final, nfa->post); + newarc(nfa, '$', 0, nfa->final, nfa->post); + + if (ISERR()) { + freenfa(nfa); + return NULL; + } + return nfa; } /* * TooManyStates - checks if the max states exceeds the compile-time value */ -static int -TooManyStates(struct nfa * nfa) -{ - struct nfa *parent = nfa->parent; - size_t sz = nfa->size; - - while (parent != NULL) - { - sz = parent->size; - parent = parent->parent; - } - if (sz > REG_MAX_STATES) - return 1; - return 0; +static int TooManyStates(struct nfa *nfa) { + struct nfa *parent = nfa->parent; + size_t sz = nfa->size; + + while (parent != NULL) { + sz = parent->size; + parent = parent->parent; + } + if (sz > REG_MAX_STATES) return 1; + return 0; } /* * IncrementSize - increases the tracked size of the NFA and its parents. */ -static void -IncrementSize(struct nfa * nfa) -{ - struct nfa *parent = nfa->parent; - - nfa->size++; - while (parent != NULL) - { - parent->size++; - parent = parent->parent; - } +static void IncrementSize(struct nfa *nfa) { + struct nfa *parent = nfa->parent; + + nfa->size++; + while (parent != NULL) { + parent->size++; + parent = parent->parent; + } } /* * DecrementSize - decreases the tracked size of the NFA and its parents. */ -static void -DecrementSize(struct nfa * nfa) -{ - struct nfa *parent = nfa->parent; - - nfa->size--; - while (parent != NULL) - { - parent->size--; - parent = parent->parent; - } +static void DecrementSize(struct nfa *nfa) { + struct nfa *parent = nfa->parent; + + nfa->size--; + while (parent != NULL) { + parent->size--; + parent = parent->parent; + } } /* * freenfa - free an entire NFA */ -static void -freenfa(struct nfa * nfa) -{ - struct state *s; - - while ((s = nfa->states) != NULL) - { - s->nins = s->nouts = 0; /* don't worry about arcs */ - freestate(nfa, s); - } - while ((s = nfa->free) != NULL) - { - nfa->free = s->next; - destroystate(nfa, s); - } - - nfa->slast = NULL; - nfa->nstates = -1; - nfa->pre = NULL; - nfa->post = NULL; - FREE(nfa); +static void freenfa(struct nfa *nfa) { + struct state *s; + + while ((s = nfa->states) != NULL) { + s->nins = s->nouts = 0; /* don't worry about arcs */ + freestate(nfa, s); + } + while ((s = nfa->free) != NULL) { + nfa->free = s->next; + destroystate(nfa, s); + } + + nfa->slast = NULL; + nfa->nstates = -1; + nfa->pre = NULL; + nfa->post = NULL; + FREE(nfa); } /* * newstate - allocate an NFA state, with zero flag value */ -static struct state * /* NULL on error */ -newstate(struct nfa * nfa) -{ - struct state *s; - - if (TooManyStates(nfa)) - { - NERR(REG_ETOOBIG); - return NULL; - } - if (nfa->free != NULL) - { - s = nfa->free; - nfa->free = s->next; - } - else - { - s = (struct state *) MALLOC(sizeof(struct state)); - if (s == NULL) - { - NERR(REG_ESPACE); - return NULL; - } - s->oas.next = NULL; - s->free = NULL; - s->noas = 0; - } - - assert(nfa->nstates >= 0); - s->no = nfa->nstates++; - s->flag = 0; - if (nfa->states == NULL) - nfa->states = s; - s->nins = 0; - s->ins = NULL; - s->nouts = 0; - s->outs = NULL; - s->tmp = NULL; - s->next = NULL; - if (nfa->slast != NULL) - { - assert(nfa->slast->next == NULL); - nfa->slast->next = s; - } - s->prev = nfa->slast; - nfa->slast = s; - /* track the current size and the parent size */ - IncrementSize(nfa); - return s; +static struct state * /* NULL on error */ +newstate(struct nfa *nfa) { + struct state *s; + + if (TooManyStates(nfa)) { + NERR(REG_ETOOBIG); + return NULL; + } + if (nfa->free != NULL) { + s = nfa->free; + nfa->free = s->next; + } else { + s = (struct state *)MALLOC(sizeof(struct state)); + if (s == NULL) { + NERR(REG_ESPACE); + return NULL; + } + s->oas.next = NULL; + s->free = NULL; + s->noas = 0; + } + + assert(nfa->nstates >= 0); + s->no = nfa->nstates++; + s->flag = 0; + if (nfa->states == NULL) nfa->states = s; + s->nins = 0; + s->ins = NULL; + s->nouts = 0; + s->outs = NULL; + s->tmp = NULL; + s->next = NULL; + if (nfa->slast != NULL) { + assert(nfa->slast->next == NULL); + nfa->slast->next = s; + } + s->prev = nfa->slast; + nfa->slast = s; + /* track the current size and the parent size */ + IncrementSize(nfa); + return s; } /* * newfstate - allocate an NFA state with a specified flag value */ -static struct state * /* NULL on error */ -newfstate(struct nfa * nfa, int flag) -{ - struct state *s; +static struct state * /* NULL on error */ +newfstate(struct nfa *nfa, int flag) { + struct state *s; - s = newstate(nfa); - if (s != NULL) - s->flag = (char) flag; - return s; + s = newstate(nfa); + if (s != NULL) s->flag = (char)flag; + return s; } /* * dropstate - delete a state's inarcs and outarcs and free it */ -static void -dropstate(struct nfa * nfa, - struct state * s) -{ - struct arc *a; +static void dropstate(struct nfa *nfa, struct state *s) { + struct arc *a; - while ((a = s->ins) != NULL) - freearc(nfa, a); - while ((a = s->outs) != NULL) - freearc(nfa, a); - freestate(nfa, s); + while ((a = s->ins) != NULL) freearc(nfa, a); + while ((a = s->outs) != NULL) freearc(nfa, a); + freestate(nfa, s); } /* * freestate - free a state, which has no in-arcs or out-arcs */ -static void -freestate(struct nfa * nfa, - struct state * s) -{ - assert(s != NULL); - assert(s->nins == 0 && s->nouts == 0); - - s->no = FREESTATE; - s->flag = 0; - if (s->next != NULL) - s->next->prev = s->prev; - else - { - assert(s == nfa->slast); - nfa->slast = s->prev; - } - if (s->prev != NULL) - s->prev->next = s->next; - else - { - assert(s == nfa->states); - nfa->states = s->next; - } - s->prev = NULL; - s->next = nfa->free; /* don't delete it, put it on the free list */ - nfa->free = s; - DecrementSize(nfa); +static void freestate(struct nfa *nfa, struct state *s) { + assert(s != NULL); + assert(s->nins == 0 && s->nouts == 0); + + s->no = FREESTATE; + s->flag = 0; + if (s->next != NULL) + s->next->prev = s->prev; + else { + assert(s == nfa->slast); + nfa->slast = s->prev; + } + if (s->prev != NULL) + s->prev->next = s->next; + else { + assert(s == nfa->states); + nfa->states = s->next; + } + s->prev = NULL; + s->next = nfa->free; /* don't delete it, put it on the free list */ + nfa->free = s; + DecrementSize(nfa); } /* * destroystate - really get rid of an already-freed state */ -static void -destroystate(struct nfa * nfa, - struct state * s) -{ - struct arcbatch *ab; - struct arcbatch *abnext; - - assert(s->no == FREESTATE); - for (ab = s->oas.next; ab != NULL; ab = abnext) - { - abnext = ab->next; - FREE(ab); - } - s->ins = NULL; - s->outs = NULL; - s->next = NULL; - FREE(s); +static void destroystate(struct nfa *nfa, struct state *s) { + struct arcbatch *ab; + struct arcbatch *abnext; + + assert(s->no == FREESTATE); + for (ab = s->oas.next; ab != NULL; ab = abnext) { + abnext = ab->next; + FREE(ab); + } + s->ins = NULL; + s->outs = NULL; + s->next = NULL; + FREE(s); } /* * newarc - set up a new arc within an NFA */ -static void -newarc(struct nfa * nfa, - int t, - pcolor co, - struct state * from, - struct state * to) -{ - struct arc *a; - - assert(from != NULL && to != NULL); - - /* check for duplicates */ - for (a = from->outs; a != NULL; a = a->outchain) - if (a->to == to && a->co == co && a->type == t) - return; - - a = allocarc(nfa, from); - if (NISERR()) - return; - assert(a != NULL); - - a->type = t; - a->co = (color) co; - a->to = to; - a->from = from; - - /* - * Put the new arc on the beginning, not the end, of the chains. Not only - * is this easier, it has the very useful side effect that deleting the - * most-recently-added arc is the cheapest case rather than the most - * expensive one. - */ - a->inchain = to->ins; - to->ins = a; - a->outchain = from->outs; - from->outs = a; - - from->nouts++; - to->nins++; - - if (COLORED(a) && nfa->parent == NULL) - colorchain(nfa->cm, a); +static void newarc(struct nfa *nfa, int t, pcolor co, struct state *from, + struct state *to) { + struct arc *a; + + assert(from != NULL && to != NULL); + + /* check for duplicates */ + for (a = from->outs; a != NULL; a = a->outchain) + if (a->to == to && a->co == co && a->type == t) return; + + a = allocarc(nfa, from); + if (NISERR()) return; + assert(a != NULL); + + a->type = t; + a->co = (color)co; + a->to = to; + a->from = from; + + /* + * Put the new arc on the beginning, not the end, of the chains. Not only + * is this easier, it has the very useful side effect that deleting the + * most-recently-added arc is the cheapest case rather than the most + * expensive one. + */ + a->inchain = to->ins; + to->ins = a; + a->outchain = from->outs; + from->outs = a; + + from->nouts++; + to->nins++; + + if (COLORED(a) && nfa->parent == NULL) colorchain(nfa->cm, a); } /* * allocarc - allocate a new out-arc within a state */ -static struct arc * /* NULL for failure */ -allocarc(struct nfa * nfa, - struct state * s) -{ - struct arc *a; - - /* shortcut */ - if (s->free == NULL && s->noas < ABSIZE) - { - a = &s->oas.a[s->noas]; - s->noas++; - return a; - } - - /* if none at hand, get more */ - if (s->free == NULL) - { - struct arcbatch *newAb; - int i; - - newAb = (struct arcbatch *) MALLOC(sizeof(struct arcbatch)); - if (newAb == NULL) - { - NERR(REG_ESPACE); - return NULL; - } - newAb->next = s->oas.next; - s->oas.next = newAb; - - for (i = 0; i < ABSIZE; i++) - { - newAb->a[i].type = 0; - newAb->a[i].freechain = &newAb->a[i + 1]; - } - newAb->a[ABSIZE - 1].freechain = NULL; - s->free = &newAb->a[0]; - } - assert(s->free != NULL); - - a = s->free; - s->free = a->freechain; - return a; +static struct arc * /* NULL for failure */ +allocarc(struct nfa *nfa, struct state *s) { + struct arc *a; + + /* shortcut */ + if (s->free == NULL && s->noas < ABSIZE) { + a = &s->oas.a[s->noas]; + s->noas++; + return a; + } + + /* if none at hand, get more */ + if (s->free == NULL) { + struct arcbatch *newAb; + int i; + + newAb = (struct arcbatch *)MALLOC(sizeof(struct arcbatch)); + if (newAb == NULL) { + NERR(REG_ESPACE); + return NULL; + } + newAb->next = s->oas.next; + s->oas.next = newAb; + + for (i = 0; i < ABSIZE; i++) { + newAb->a[i].type = 0; + newAb->a[i].freechain = &newAb->a[i + 1]; + } + newAb->a[ABSIZE - 1].freechain = NULL; + s->free = &newAb->a[0]; + } + assert(s->free != NULL); + + a = s->free; + s->free = a->freechain; + return a; } /* * freearc - free an arc */ -static void -freearc(struct nfa * nfa, - struct arc * victim) -{ - struct state *from = victim->from; - struct state *to = victim->to; - struct arc *a; - - assert(victim->type != 0); - - /* take it off color chain if necessary */ - if (COLORED(victim) && nfa->parent == NULL) - uncolorchain(nfa->cm, victim); - - /* take it off source's out-chain */ - assert(from != NULL); - assert(from->outs != NULL); - a = from->outs; - if (a == victim) /* simple case: first in chain */ - from->outs = victim->outchain; - else - { - for (; a != NULL && a->outchain != victim; a = a->outchain) - continue; - assert(a != NULL); - a->outchain = victim->outchain; - } - from->nouts--; - - /* take it off target's in-chain */ - assert(to != NULL); - assert(to->ins != NULL); - a = to->ins; - if (a == victim) /* simple case: first in chain */ - to->ins = victim->inchain; - else - { - for (; a != NULL && a->inchain != victim; a = a->inchain) - continue; - assert(a != NULL); - a->inchain = victim->inchain; - } - to->nins--; - - /* clean up and place on free list */ - victim->type = 0; - victim->from = NULL; /* precautions... */ - victim->to = NULL; - victim->inchain = NULL; - victim->outchain = NULL; - victim->freechain = from->free; - from->free = victim; +static void freearc(struct nfa *nfa, struct arc *victim) { + struct state *from = victim->from; + struct state *to = victim->to; + struct arc *a; + + assert(victim->type != 0); + + /* take it off color chain if necessary */ + if (COLORED(victim) && nfa->parent == NULL) uncolorchain(nfa->cm, victim); + + /* take it off source's out-chain */ + assert(from != NULL); + assert(from->outs != NULL); + a = from->outs; + if (a == victim) /* simple case: first in chain */ + from->outs = victim->outchain; + else { + for (; a != NULL && a->outchain != victim; a = a->outchain) continue; + assert(a != NULL); + a->outchain = victim->outchain; + } + from->nouts--; + + /* take it off target's in-chain */ + assert(to != NULL); + assert(to->ins != NULL); + a = to->ins; + if (a == victim) /* simple case: first in chain */ + to->ins = victim->inchain; + else { + for (; a != NULL && a->inchain != victim; a = a->inchain) continue; + assert(a != NULL); + a->inchain = victim->inchain; + } + to->nins--; + + /* clean up and place on free list */ + victim->type = 0; + victim->from = NULL; /* precautions... */ + victim->to = NULL; + victim->inchain = NULL; + victim->outchain = NULL; + victim->freechain = from->free; + from->free = victim; +} + +/* + * hasnonemptyout - Does state have a non-EMPTY out arc? + */ +static int hasnonemptyout(struct state *s) { + struct arc *a; + + for (a = s->outs; a != NULL; a = a->outchain) { + if (a->type != EMPTY) return 1; + } + return 0; +} + +/* + * nonemptyouts - count non-EMPTY out arcs of a state + */ +static int nonemptyouts(struct state *s) { + int n = 0; + struct arc *a; + + for (a = s->outs; a != NULL; a = a->outchain) { + if (a->type != EMPTY) n++; + } + return n; +} + +/* + * nonemptyins - count non-EMPTY in arcs of a state + */ +static int nonemptyins(struct state *s) { + int n = 0; + struct arc *a; + + for (a = s->ins; a != NULL; a = a->inchain) { + if (a->type != EMPTY) n++; + } + return n; } /* * findarc - find arc, if any, from given source with given type and color * If there is more than one such arc, the result is random. */ -static struct arc * -findarc(struct state * s, - int type, - pcolor co) -{ - struct arc *a; +static struct arc *findarc(struct state *s, int type, pcolor co) { + struct arc *a; - for (a = s->outs; a != NULL; a = a->outchain) - if (a->type == type && a->co == co) - return a; - return NULL; + for (a = s->outs; a != NULL; a = a->outchain) + if (a->type == type && a->co == co) return a; + return NULL; } /* * cparc - allocate a new arc within an NFA, copying details from old one */ -static void -cparc(struct nfa * nfa, - struct arc * oa, - struct state * from, - struct state * to) -{ - newarc(nfa, oa->type, oa->co, from, to); +static void cparc(struct nfa *nfa, struct arc *oa, struct state *from, + struct state *to) { + newarc(nfa, oa->type, oa->co, from, to); } /* @@ -492,91 +457,78 @@ cparc(struct nfa * nfa, * for duplicate suppression, which makes it easier to just make new * ones to exploit the suppression built into newarc. */ -static void -moveins(struct nfa * nfa, - struct state * oldState, - struct state * newState) -{ - struct arc *a; - - assert(oldState != newState); - - while ((a = oldState->ins) != NULL) - { - cparc(nfa, a, a->from, newState); - freearc(nfa, a); - } - assert(oldState->nins == 0); - assert(oldState->ins == NULL); +static void moveins(struct nfa *nfa, struct state *oldState, + struct state *newState) { + struct arc *a; + + assert(oldState != newState); + + while ((a = oldState->ins) != NULL) { + cparc(nfa, a, a->from, newState); + freearc(nfa, a); + } + assert(oldState->nins == 0); + assert(oldState->ins == NULL); } /* - * copyins - copy all in arcs of a state to another state + * copyins - copy in arcs of a state to another state + * + * Either all arcs, or only non-empty ones as determined by all value. */ -static void -copyins(struct nfa * nfa, - struct state * oldState, - struct state * newState) -{ - struct arc *a; +static void copyins(struct nfa *nfa, struct state *oldState, + struct state *newState, int all) { + struct arc *a; - assert(oldState != newState); + assert(oldState != newState); - for (a = oldState->ins; a != NULL; a = a->inchain) - cparc(nfa, a, a->from, newState); + for (a = oldState->ins; a != NULL; a = a->inchain) { + if (all || a->type != EMPTY) cparc(nfa, a, a->from, newState); + } } /* * moveouts - move all out arcs of a state to another state */ -static void -moveouts(struct nfa * nfa, - struct state * oldState, - struct state * newState) -{ - struct arc *a; +static void moveouts(struct nfa *nfa, struct state *oldState, + struct state *newState) { + struct arc *a; - assert(oldState != newState); + assert(oldState != newState); - while ((a = oldState->outs) != NULL) - { - cparc(nfa, a, newState, a->to); - freearc(nfa, a); - } + while ((a = oldState->outs) != NULL) { + cparc(nfa, a, newState, a->to); + freearc(nfa, a); + } } /* - * copyouts - copy all out arcs of a state to another state + * copyouts - copy out arcs of a state to another state + * + * Either all arcs, or only non-empty ones as determined by all value. */ -static void -copyouts(struct nfa * nfa, - struct state * oldState, - struct state * newState) -{ - struct arc *a; +static void copyouts(struct nfa *nfa, struct state *oldState, + struct state *newState, int all) { + struct arc *a; - assert(oldState != newState); + assert(oldState != newState); - for (a = oldState->outs; a != NULL; a = a->outchain) - cparc(nfa, a, newState, a->to); + for (a = oldState->outs; a != NULL; a = a->outchain) { + if (all || a->type != EMPTY) cparc(nfa, a, newState, a->to); + } } /* * cloneouts - copy out arcs of a state to another state pair, modifying type */ -static void -cloneouts(struct nfa * nfa, - struct state * old, - struct state * from, - struct state * to, - int type) -{ - struct arc *a; +static void cloneouts(struct nfa *nfa, struct state *old, struct state *from, + struct state *to, int type) { + struct arc *a; - assert(old != from); + assert(old != from); - for (a = old->outs; a != NULL; a = a->outchain) - newarc(nfa, type, a->co, from, to); + for (a = old->outs; a != NULL; a = a->outchain) + newarc(nfa, type, a->co, from, to); } /* @@ -585,60 +537,52 @@ cloneouts(struct nfa * nfa, * This uses a recursive traversal of the sub-NFA, marking already-seen * states using their tmp pointer. */ -static void -delsub(struct nfa * nfa, - struct state * lp, /* the sub-NFA goes from here... */ - struct state * rp) /* ...to here, *not* inclusive */ +static void delsub(struct nfa *nfa, + struct state *lp, /* the sub-NFA goes from here... */ + struct state *rp) /* ...to here, *not* inclusive */ { - assert(lp != rp); + assert(lp != rp); - rp->tmp = rp; /* mark end */ + rp->tmp = rp; /* mark end */ - deltraverse(nfa, lp, lp); - assert(lp->nouts == 0 && rp->nins == 0); /* did the job */ - assert(lp->no != FREESTATE && rp->no != FREESTATE); /* no more */ + deltraverse(nfa, lp, lp); + assert(lp->nouts == 0 && rp->nins == 0); /* did the job */ + assert(lp->no != FREESTATE && rp->no != FREESTATE); /* no more */ - rp->tmp = NULL; /* unmark end */ - lp->tmp = NULL; /* and begin, marked by deltraverse */ + rp->tmp = NULL; /* unmark end */ + lp->tmp = NULL; /* and begin, marked by deltraverse */ } /* * deltraverse - the recursive heart of delsub * This routine's basic job is to destroy all out-arcs of the state. */ -static void -deltraverse(struct nfa * nfa, - struct state * leftend, - struct state * s) -{ - struct arc *a; - struct state *to; - - if (s->nouts == 0) - return; /* nothing to do */ - if (s->tmp != NULL) - return; /* already in progress */ - - s->tmp = s; /* mark as in progress */ - - while ((a = s->outs) != NULL) - { - to = a->to; - deltraverse(nfa, leftend, to); - assert(to->nouts == 0 || to->tmp != NULL); - freearc(nfa, a); - if (to->nins == 0 && to->tmp == NULL) - { - assert(to->nouts == 0); - freestate(nfa, to); - } - } - - assert(s->no != FREESTATE); /* we're still here */ - assert(s == leftend || s->nins != 0); /* and still reachable */ - assert(s->nouts == 0); /* but have no outarcs */ - - s->tmp = NULL; /* we're done here */ +static void deltraverse(struct nfa *nfa, struct state *leftend, + struct state *s) { + struct arc *a; + struct state *to; + + if (s->nouts == 0) return; /* nothing to do */ + if (s->tmp != NULL) return; /* already in progress */ + + s->tmp = s; /* mark as in progress */ + + while ((a = s->outs) != NULL) { + to = a->to; + deltraverse(nfa, leftend, to); + assert(to->nouts == 0 || to->tmp != NULL); + freearc(nfa, a); + if (to->nins == 0 && to->tmp == NULL) { + assert(to->nouts == 0); + freestate(nfa, to); + } + } + + assert(s->no != FREESTATE); /* we're still here */ + assert(s == leftend || s->nins != 0); /* and still reachable */ + assert(s->nouts == 0); /* but have no outarcs */ + + s->tmp = NULL; /* we're done here */ } /* @@ -648,181 +592,147 @@ deltraverse(struct nfa * nfa, * as well as mark already-seen states. (You knew there was a reason why * it's a state pointer, didn't you? :-)) */ -static void -dupnfa(struct nfa * nfa, - struct state * start, /* duplicate of subNFA starting here */ - struct state * stop, /* and stopping here */ - struct state * from, /* stringing duplicate from here */ - struct state * to) /* to here */ +static void dupnfa(struct nfa *nfa, + struct state *start, /* duplicate of subNFA starting here */ + struct state *stop, /* and stopping here */ + struct state *from, /* stringing duplicate from here */ + struct state *to) /* to here */ { - if (start == stop) - { - newarc(nfa, EMPTY, 0, from, to); - return; - } - - stop->tmp = to; - duptraverse(nfa, start, from); - /* done, except for clearing out the tmp pointers */ - - stop->tmp = NULL; - cleartraverse(nfa, start); + if (start == stop) { + newarc(nfa, EMPTY, 0, from, to); + return; + } + + stop->tmp = to; + duptraverse(nfa, start, from); + /* done, except for clearing out the tmp pointers */ + + stop->tmp = NULL; + cleartraverse(nfa, start); } /* * duptraverse - recursive heart of dupnfa */ -static void -duptraverse(struct nfa * nfa, - struct state * s, - struct state * stmp) /* s's duplicate, or NULL */ +static void duptraverse(struct nfa *nfa, struct state *s, + struct state *stmp) /* s's duplicate, or NULL */ { - struct arc *a; - - if (s->tmp != NULL) - return; /* already done */ - - s->tmp = (stmp == NULL) ? newstate(nfa) : stmp; - if (s->tmp == NULL) - { - assert(NISERR()); - return; - } - - for (a = s->outs; a != NULL && !NISERR(); a = a->outchain) - { - duptraverse(nfa, a->to, (struct state *) NULL); - if (NISERR()) - break; - assert(a->to->tmp != NULL); - cparc(nfa, a, s->tmp, a->to->tmp); - } + struct arc *a; + + if (s->tmp != NULL) return; /* already done */ + + s->tmp = (stmp == NULL) ? newstate(nfa) : stmp; + if (s->tmp == NULL) { + assert(NISERR()); + return; + } + + for (a = s->outs; a != NULL && !NISERR(); a = a->outchain) { + duptraverse(nfa, a->to, (struct state *)NULL); + if (NISERR()) break; + assert(a->to->tmp != NULL); + cparc(nfa, a, s->tmp, a->to->tmp); + } } /* * cleartraverse - recursive cleanup for algorithms that leave tmp ptrs set */ -static void -cleartraverse(struct nfa * nfa, - struct state * s) -{ - struct arc *a; +static void cleartraverse(struct nfa *nfa, struct state *s) { + struct arc *a; - if (s->tmp == NULL) - return; - s->tmp = NULL; + if (s->tmp == NULL) return; + s->tmp = NULL; - for (a = s->outs; a != NULL; a = a->outchain) - cleartraverse(nfa, a->to); + for (a = s->outs; a != NULL; a = a->outchain) cleartraverse(nfa, a->to); } /* * specialcolors - fill in special colors for an NFA */ -static void -specialcolors(struct nfa * nfa) -{ - /* false colors for BOS, BOL, EOS, EOL */ - if (nfa->parent == NULL) - { - nfa->bos[0] = pseudocolor(nfa->cm); - nfa->bos[1] = pseudocolor(nfa->cm); - nfa->eos[0] = pseudocolor(nfa->cm); - nfa->eos[1] = pseudocolor(nfa->cm); - } - else - { - assert(nfa->parent->bos[0] != COLORLESS); - nfa->bos[0] = nfa->parent->bos[0]; - assert(nfa->parent->bos[1] != COLORLESS); - nfa->bos[1] = nfa->parent->bos[1]; - assert(nfa->parent->eos[0] != COLORLESS); - nfa->eos[0] = nfa->parent->eos[0]; - assert(nfa->parent->eos[1] != COLORLESS); - nfa->eos[1] = nfa->parent->eos[1]; - } +static void specialcolors(struct nfa *nfa) { + /* false colors for BOS, BOL, EOS, EOL */ + if (nfa->parent == NULL) { + nfa->bos[0] = pseudocolor(nfa->cm); + nfa->bos[1] = pseudocolor(nfa->cm); + nfa->eos[0] = pseudocolor(nfa->cm); + nfa->eos[1] = pseudocolor(nfa->cm); + } else { + assert(nfa->parent->bos[0] != COLORLESS); + nfa->bos[0] = nfa->parent->bos[0]; + assert(nfa->parent->bos[1] != COLORLESS); + nfa->bos[1] = nfa->parent->bos[1]; + assert(nfa->parent->eos[0] != COLORLESS); + nfa->eos[0] = nfa->parent->eos[0]; + assert(nfa->parent->eos[1] != COLORLESS); + nfa->eos[1] = nfa->parent->eos[1]; + } } /* * optimize - optimize an NFA */ -static long /* re_info bits */ -optimize(struct nfa * nfa, - FILE *f) /* for debug output; NULL none */ +static long /* re_info bits */ +optimize(struct nfa *nfa, FILE *f) /* for debug output; NULL none */ { #ifdef REG_DEBUG - int verbose = (f != NULL) ? 1 : 0; + int verbose = (f != NULL) ? 1 : 0; - if (verbose) - fprintf(f, "\ninitial cleanup:\n"); + if (verbose) fprintf(f, "\ninitial cleanup:\n"); #endif - cleanup(nfa); /* may simplify situation */ + cleanup(nfa); /* may simplify situation */ #ifdef REG_DEBUG - if (verbose) - dumpnfa(nfa, f); - if (verbose) - fprintf(f, "\nempties:\n"); + if (verbose) dumpnfa(nfa, f); + if (verbose) fprintf(f, "\nempties:\n"); #endif - fixempties(nfa, f); /* get rid of EMPTY arcs */ + fixempties(nfa, f); /* get rid of EMPTY arcs */ #ifdef REG_DEBUG - if (verbose) - fprintf(f, "\nconstraints:\n"); + if (verbose) fprintf(f, "\nconstraints:\n"); #endif - pullback(nfa, f); /* pull back constraints backward */ - pushfwd(nfa, f); /* push fwd constraints forward */ + pullback(nfa, f); /* pull back constraints backward */ + pushfwd(nfa, f); /* push fwd constraints forward */ #ifdef REG_DEBUG - if (verbose) - fprintf(f, "\nfinal cleanup:\n"); + if (verbose) fprintf(f, "\nfinal cleanup:\n"); #endif - cleanup(nfa); /* final tidying */ - return analyze(nfa); /* and analysis */ + cleanup(nfa); /* final tidying */ + return analyze(nfa); /* and analysis */ } /* * pullback - pull back constraints backward to (with luck) eliminate them */ -static void -pullback(struct nfa * nfa, - FILE *f) /* for debug output; NULL none */ +static void pullback(struct nfa *nfa, FILE *f) /* for debug output; NULL none */ { - struct state *s; - struct state *nexts; - struct arc *a; - struct arc *nexta; - int progress; - - /* find and pull until there are no more */ - do - { - progress = 0; - for (s = nfa->states; s != NULL && !NISERR(); s = nexts) - { - nexts = s->next; - for (a = s->outs; a != NULL && !NISERR(); a = nexta) - { - nexta = a->outchain; - if (a->type == '^' || a->type == BEHIND) - if (pull(nfa, a)) - progress = 1; - assert(nexta == NULL || s->no != FREESTATE); - } - } - if (progress && f != NULL) - dumpnfa(nfa, f); - } while (progress && !NISERR()); - if (NISERR()) - return; - - for (a = nfa->pre->outs; a != NULL; a = nexta) - { - nexta = a->outchain; - if (a->type == '^') - { - assert(a->co == 0 || a->co == 1); - newarc(nfa, PLAIN, nfa->bos[a->co], a->from, a->to); - freearc(nfa, a); - } - } + struct state *s; + struct state *nexts; + struct arc *a; + struct arc *nexta; + int progress; + + /* find and pull until there are no more */ + do { + progress = 0; + for (s = nfa->states; s != NULL && !NISERR(); s = nexts) { + nexts = s->next; + for (a = s->outs; a != NULL && !NISERR(); a = nexta) { + nexta = a->outchain; + if (a->type == '^' || a->type == BEHIND) + if (pull(nfa, a)) progress = 1; + assert(nexta == NULL || s->no != FREESTATE); + } + } + if (progress && f != NULL) dumpnfa(nfa, f); + } while (progress && !NISERR()); + if (NISERR()) return; + + for (a = nfa->pre->outs; a != NULL; a = nexta) { + nexta = a->outchain; + if (a->type == '^') { + assert(a->co == 0 || a->co == 1); + newarc(nfa, PLAIN, nfa->bos[a->co], a->from, a->to); + freearc(nfa, a); + } + } } /* @@ -831,142 +741,119 @@ pullback(struct nfa * nfa, * one state -- the constraint's from state -- and only if the constraint * was that state's last outarc. */ -static int /* 0 couldn't, 1 could */ -pull(struct nfa * nfa, - struct arc * con) -{ - struct state *from = con->from; - struct state *to = con->to; - struct arc *a; - struct arc *nexta; - struct state *s; - - if (from == to) - { /* circular constraint is pointless */ - freearc(nfa, con); - return 1; - } - if (from->flag) /* can't pull back beyond start */ - return 0; - if (from->nins == 0) - { /* unreachable */ - freearc(nfa, con); - return 1; - } - - /* - * DGP 2007-11-15: Cloning a state with a circular constraint on its list - * of outs can lead to trouble [Tcl Bug 1810038], so get rid of them - * first. - */ - for (a = from->outs; a != NULL; a = nexta) - { - nexta = a->outchain; - switch (a->type) - { - case '^': - case '$': - case BEHIND: - case AHEAD: - if (from == a->to) - freearc(nfa, a); - break; - } - } - - /* first, clone from state if necessary to avoid other outarcs */ - if (from->nouts > 1) - { - s = newstate(nfa); - if (NISERR()) - return 0; - assert(to != from); /* con is not an inarc */ - copyins(nfa, from, s); /* duplicate inarcs */ - cparc(nfa, con, s, to); /* move constraint arc */ - freearc(nfa, con); - from = s; - con = from->outs; - } - assert(from->nouts == 1); - - /* propagate the constraint into the from state's inarcs */ - for (a = from->ins; a != NULL; a = nexta) - { - nexta = a->inchain; - switch (combine(con, a)) - { - case INCOMPATIBLE: /* destroy the arc */ - freearc(nfa, a); - break; - case SATISFIED: /* no action needed */ - break; - case COMPATIBLE: /* swap the two arcs, more or less */ - s = newstate(nfa); - if (NISERR()) - return 0; - cparc(nfa, a, s, to); /* anticipate move */ - cparc(nfa, con, a->from, s); - if (NISERR()) - return 0; - freearc(nfa, a); - break; - default: - assert(NOTREACHED); - break; - } - } - - /* remaining inarcs, if any, incorporate the constraint */ - moveins(nfa, from, to); - dropstate(nfa, from); /* will free the constraint */ - return 1; +static int /* 0 couldn't, 1 could */ +pull(struct nfa *nfa, struct arc *con) { + struct state *from = con->from; + struct state *to = con->to; + struct arc *a; + struct arc *nexta; + struct state *s; + + if (from == to) { /* circular constraint is pointless */ + freearc(nfa, con); + return 1; + } + if (from->flag) /* can't pull back beyond start */ + return 0; + if (from->nins == 0) { /* unreachable */ + freearc(nfa, con); + return 1; + } + + /* + * DGP 2007-11-15: Cloning a state with a circular constraint on its list + * of outs can lead to trouble [Tcl Bug 1810038], so get rid of them + * first. + */ + for (a = from->outs; a != NULL; a = nexta) { + nexta = a->outchain; + switch (a->type) { + case '^': + case '$': + case BEHIND: + case AHEAD: + if (from == a->to) freearc(nfa, a); + break; + } + } + + /* first, clone from state if necessary to avoid other outarcs */ + if (from->nouts > 1) { + s = newstate(nfa); + if (NISERR()) return 0; + assert(to != from); /* con is not an inarc */ + copyins(nfa, from, s, 1); /* duplicate inarcs */ + cparc(nfa, con, s, to); /* move constraint arc */ + freearc(nfa, con); + from = s; + con = from->outs; + } + assert(from->nouts == 1); + + /* propagate the constraint into the from state's inarcs */ + for (a = from->ins; a != NULL; a = nexta) { + nexta = a->inchain; + switch (combine(con, a)) { + case INCOMPATIBLE: /* destroy the arc */ + freearc(nfa, a); + break; + case SATISFIED: /* no action needed */ + break; + case COMPATIBLE: /* swap the two arcs, more or less */ + s = newstate(nfa); + if (NISERR()) return 0; + cparc(nfa, a, s, to); /* anticipate move */ + cparc(nfa, con, a->from, s); + if (NISERR()) return 0; + freearc(nfa, a); + break; + default: + assert(NOTREACHED); + break; + } + } + + /* remaining inarcs, if any, incorporate the constraint */ + moveins(nfa, from, to); + dropstate(nfa, from); /* will free the constraint */ + return 1; } /* * pushfwd - push forward constraints forward to (with luck) eliminate them */ -static void -pushfwd(struct nfa * nfa, - FILE *f) /* for debug output; NULL none */ +static void pushfwd(struct nfa *nfa, FILE *f) /* for debug output; NULL none */ { - struct state *s; - struct state *nexts; - struct arc *a; - struct arc *nexta; - int progress; - - /* find and push until there are no more */ - do - { - progress = 0; - for (s = nfa->states; s != NULL && !NISERR(); s = nexts) - { - nexts = s->next; - for (a = s->ins; a != NULL && !NISERR(); a = nexta) - { - nexta = a->inchain; - if (a->type == '$' || a->type == AHEAD) - if (push(nfa, a)) - progress = 1; - assert(nexta == NULL || s->no != FREESTATE); - } - } - if (progress && f != NULL) - dumpnfa(nfa, f); - } while (progress && !NISERR()); - if (NISERR()) - return; - - for (a = nfa->post->ins; a != NULL; a = nexta) - { - nexta = a->inchain; - if (a->type == '$') - { - assert(a->co == 0 || a->co == 1); - newarc(nfa, PLAIN, nfa->eos[a->co], a->from, a->to); - freearc(nfa, a); - } - } + struct state *s; + struct state *nexts; + struct arc *a; + struct arc *nexta; + int progress; + + /* find and push until there are no more */ + do { + progress = 0; + for (s = nfa->states; s != NULL && !NISERR(); s = nexts) { + nexts = s->next; + for (a = s->ins; a != NULL && !NISERR(); a = nexta) { + nexta = a->inchain; + if (a->type == '$' || a->type == AHEAD) + if (push(nfa, a)) progress = 1; + assert(nexta == NULL || s->no != FREESTATE); + } + } + if (progress && f != NULL) dumpnfa(nfa, f); + } while (progress && !NISERR()); + if (NISERR()) return; + + for (a = nfa->post->ins; a != NULL; a = nexta) { + nexta = a->inchain; + if (a->type == '$') { + assert(a->co == 0 || a->co == 1); + newarc(nfa, PLAIN, nfa->eos[a->co], a->from, a->to); + freearc(nfa, a); + } + } } /* @@ -975,97 +862,84 @@ pushfwd(struct nfa * nfa, * one state -- the constraint's to state -- and only if the constraint * was that state's last inarc. */ -static int /* 0 couldn't, 1 could */ -push(struct nfa * nfa, - struct arc * con) -{ - struct state *from = con->from; - struct state *to = con->to; - struct arc *a; - struct arc *nexta; - struct state *s; - - if (to == from) - { /* circular constraint is pointless */ - freearc(nfa, con); - return 1; - } - if (to->flag) /* can't push forward beyond end */ - return 0; - if (to->nouts == 0) - { /* dead end */ - freearc(nfa, con); - return 1; - } - - /* - * DGP 2007-11-15: Here we duplicate the same protections as appear in - * pull() above to avoid troubles with cloning a state with a circular - * constraint on its list of ins. It is not clear whether this is - * necessary, or is protecting against a "can't happen". Any test case - * that actually leads to a freearc() call here would be a welcome - * addition to the test suite. - */ - for (a = to->ins; a != NULL; a = nexta) - { - nexta = a->inchain; - switch (a->type) - { - case '^': - case '$': - case BEHIND: - case AHEAD: - if (a->from == to) - freearc(nfa, a); - break; - } - } - - /* first, clone to state if necessary to avoid other inarcs */ - if (to->nins > 1) - { - s = newstate(nfa); - if (NISERR()) - return 0; - copyouts(nfa, to, s); /* duplicate outarcs */ - cparc(nfa, con, from, s); /* move constraint */ - freearc(nfa, con); - to = s; - con = to->ins; - } - assert(to->nins == 1); - - /* propagate the constraint into the to state's outarcs */ - for (a = to->outs; a != NULL; a = nexta) - { - nexta = a->outchain; - switch (combine(con, a)) - { - case INCOMPATIBLE: /* destroy the arc */ - freearc(nfa, a); - break; - case SATISFIED: /* no action needed */ - break; - case COMPATIBLE: /* swap the two arcs, more or less */ - s = newstate(nfa); - if (NISERR()) - return 0; - cparc(nfa, con, s, a->to); /* anticipate move */ - cparc(nfa, a, from, s); - if (NISERR()) - return 0; - freearc(nfa, a); - break; - default: - assert(NOTREACHED); - break; - } - } - - /* remaining outarcs, if any, incorporate the constraint */ - moveouts(nfa, to, from); - dropstate(nfa, to); /* will free the constraint */ - return 1; +static int /* 0 couldn't, 1 could */ +push(struct nfa *nfa, struct arc *con) { + struct state *from = con->from; + struct state *to = con->to; + struct arc *a; + struct arc *nexta; + struct state *s; + + if (to == from) { /* circular constraint is pointless */ + freearc(nfa, con); + return 1; + } + if (to->flag) /* can't push forward beyond end */ + return 0; + if (to->nouts == 0) { /* dead end */ + freearc(nfa, con); + return 1; + } + + /* + * DGP 2007-11-15: Here we duplicate the same protections as appear in + * pull() above to avoid troubles with cloning a state with a circular + * constraint on its list of ins. It is not clear whether this is + * necessary, or is protecting against a "can't happen". Any test case + * that actually leads to a freearc() call here would be a welcome + * addition to the test suite. + */ + for (a = to->ins; a != NULL; a = nexta) { + nexta = a->inchain; + switch (a->type) { + case '^': + case '$': + case BEHIND: + case AHEAD: + if (a->from == to) freearc(nfa, a); + break; + } + } + + /* first, clone to state if necessary to avoid other inarcs */ + if (to->nins > 1) { + s = newstate(nfa); + if (NISERR()) return 0; + copyouts(nfa, to, s, 1); /* duplicate outarcs */ + cparc(nfa, con, from, s); /* move constraint */ + freearc(nfa, con); + to = s; + con = to->ins; + } + assert(to->nins == 1); + + /* propagate the constraint into the to state's outarcs */ + for (a = to->outs; a != NULL; a = nexta) { + nexta = a->outchain; + switch (combine(con, a)) { + case INCOMPATIBLE: /* destroy the arc */ + freearc(nfa, a); + break; + case SATISFIED: /* no action needed */ + break; + case COMPATIBLE: /* swap the two arcs, more or less */ + s = newstate(nfa); + if (NISERR()) return 0; + cparc(nfa, con, s, a->to); /* anticipate move */ + cparc(nfa, a, from, s); + if (NISERR()) return 0; + freearc(nfa, a); + break; + default: + assert(NOTREACHED); + break; + } + } + + /* remaining outarcs, if any, incorporate the constraint */ + moveouts(nfa, to, from); + dropstate(nfa, to); /* will free the constraint */ + return 1; } /* @@ -1075,325 +949,383 @@ push(struct nfa * nfa, * #def SATISFIED 2 // constraint satisfied * #def COMPATIBLE 3 // compatible but not satisfied yet */ -static int -combine(struct arc * con, - struct arc * a) -{ -#define CA(ct,at) (((ct)<<CHAR_BIT) | (at)) - - switch (CA(con->type, a->type)) - { - case CA('^', PLAIN): /* newlines are handled separately */ - case CA('$', PLAIN): - return INCOMPATIBLE; - break; - case CA(AHEAD, PLAIN): /* color constraints meet colors */ - case CA(BEHIND, PLAIN): - if (con->co == a->co) - return SATISFIED; - return INCOMPATIBLE; - break; - case CA('^', '^'): /* collision, similar constraints */ - case CA('$', '$'): - case CA(AHEAD, AHEAD): - case CA(BEHIND, BEHIND): - if (con->co == a->co) /* true duplication */ - return SATISFIED; - return INCOMPATIBLE; - break; - case CA('^', BEHIND): /* collision, dissimilar constraints */ - case CA(BEHIND, '^'): - case CA('$', AHEAD): - case CA(AHEAD, '$'): - return INCOMPATIBLE; - break; - case CA('^', '$'): /* constraints passing each other */ - case CA('^', AHEAD): - case CA(BEHIND, '$'): - case CA(BEHIND, AHEAD): - case CA('$', '^'): - case CA('$', BEHIND): - case CA(AHEAD, '^'): - case CA(AHEAD, BEHIND): - case CA('^', LACON): - case CA(BEHIND, LACON): - case CA('$', LACON): - case CA(AHEAD, LACON): - return COMPATIBLE; - break; - } - assert(NOTREACHED); - return INCOMPATIBLE; /* for benefit of blind compilers */ +static int combine(struct arc *con, struct arc *a) { +#define CA(ct, at) (((ct) << CHAR_BIT) | (at)) + + switch (CA(con->type, a->type)) { + case CA('^', PLAIN): /* newlines are handled separately */ + case CA('$', PLAIN): + return INCOMPATIBLE; + break; + case CA(AHEAD, PLAIN): /* color constraints meet colors */ + case CA(BEHIND, PLAIN): + if (con->co == a->co) return SATISFIED; + return INCOMPATIBLE; + break; + case CA('^', '^'): /* collision, similar constraints */ + case CA('$', '$'): + case CA(AHEAD, AHEAD): + case CA(BEHIND, BEHIND): + if (con->co == a->co) /* true duplication */ + return SATISFIED; + return INCOMPATIBLE; + break; + case CA('^', BEHIND): /* collision, dissimilar constraints */ + case CA(BEHIND, '^'): + case CA('$', AHEAD): + case CA(AHEAD, '$'): + return INCOMPATIBLE; + break; + case CA('^', '$'): /* constraints passing each other */ + case CA('^', AHEAD): + case CA(BEHIND, '$'): + case CA(BEHIND, AHEAD): + case CA('$', '^'): + case CA('$', BEHIND): + case CA(AHEAD, '^'): + case CA(AHEAD, BEHIND): + case CA('^', LACON): + case CA(BEHIND, LACON): + case CA('$', LACON): + case CA(AHEAD, LACON): + return COMPATIBLE; + break; + } + assert(NOTREACHED); + return INCOMPATIBLE; /* for benefit of blind compilers */ } /* * fixempties - get rid of EMPTY arcs */ -static void -fixempties(struct nfa * nfa, - FILE *f) /* for debug output; NULL none */ +static void fixempties(struct nfa *nfa, + FILE *f) /* for debug output; NULL none */ { - struct state *s; - struct state *nexts; - struct arc *a; - struct arc *nexta; - int progress; - - /* find and eliminate empties until there are no more */ - do - { - progress = 0; - for (s = nfa->states; s != NULL && !NISERR() && - s->no != FREESTATE; s = nexts) - { - nexts = s->next; - for (a = s->outs; a != NULL && !NISERR(); a = nexta) - { - nexta = a->outchain; - if (a->type == EMPTY && unempty(nfa, a)) - progress = 1; - assert(nexta == NULL || s->no != FREESTATE); - } - } - if (progress && f != NULL) - dumpnfa(nfa, f); - } while (progress && !NISERR()); + struct state *s; + struct state *s2; + struct state *nexts; + struct arc *a; + struct arc *nexta; + + /* + * First, get rid of any states whose sole out-arc is an EMPTY, since + * they're basically just aliases for their successor. The parsing + * algorithm creates enough of these that it's worth special-casing this. + */ + for (s = nfa->states; s != NULL && !NISERR(); s = nexts) { + nexts = s->next; + if (s->flag || s->nouts != 1) continue; + a = s->outs; + assert(a != NULL && a->outchain == NULL); + if (a->type != EMPTY) continue; + if (s != a->to) moveins(nfa, s, a->to); + dropstate(nfa, s); + } + + /* + * Similarly, get rid of any state with a single EMPTY in-arc, by folding + * it into its predecessor. + */ + for (s = nfa->states; s != NULL && !NISERR(); s = nexts) { + nexts = s->next; + /* while we're at it, ensure tmp fields are clear for next step */ + assert(s->tmp == NULL); + if (s->flag || s->nins != 1) continue; + a = s->ins; + assert(a != NULL && a->inchain == NULL); + if (a->type != EMPTY) continue; + if (s != a->from) moveouts(nfa, s, a->from); + dropstate(nfa, s); + } + + /* + * For each remaining NFA state, find all other states that are reachable + * from it by a chain of one or more EMPTY arcs. Then generate new arcs + * that eliminate the need for each such chain. + * + * If we just do this straightforwardly, the algorithm gets slow in + * complex graphs, because the same arcs get copied to all intermediate + * states of an EMPTY chain, and then uselessly pushed repeatedly to the + * chain's final state; we waste a lot of time in newarc's duplicate + * checking. To improve matters, we decree that any state with only EMPTY + * out-arcs is "doomed" and will not be part of the final NFA. That can be + * ensured by not adding any new out-arcs to such a state. Having ensured + * that, we need not update the state's in-arcs list either; all arcs that + * might have gotten pushed forward to it will just get pushed directly to + * successor states. This eliminates most of the useless duplicate arcs. + */ + for (s = nfa->states; s != NULL && !NISERR(); s = s->next) { + for (s2 = emptyreachable(s, s); s2 != s && !NISERR(); s2 = nexts) { + /* + * If s2 is doomed, we decide that (1) we will always push arcs + * forward to it, not pull them back to s; and (2) we can optimize + * away the push-forward, per comment above. So do nothing. + */ + if (s2->flag || hasnonemptyout(s2)) replaceempty(nfa, s, s2); + + /* Reset the tmp fields as we walk back */ + nexts = s2->tmp; + s2->tmp = NULL; + } + s->tmp = NULL; + } + + if (NISERR()) return; + + /* + * Now remove all the EMPTY arcs, since we don't need them anymore. + */ + for (s = nfa->states; s != NULL; s = s->next) { + for (a = s->outs; a != NULL; a = nexta) { + nexta = a->outchain; + if (a->type == EMPTY) freearc(nfa, a); + } + } + + /* + * And remove any states that have become useless. (This cleanup is not + * very thorough, and would be even less so if we tried to combine it with + * the previous step; but cleanup() will take care of anything we miss.) + */ + for (s = nfa->states; s != NULL; s = nexts) { + nexts = s->next; + if ((s->nins == 0 || s->nouts == 0) && !s->flag) dropstate(nfa, s); + } + + if (f != NULL) dumpnfa(nfa, f); } /* - * unempty - optimize out an EMPTY arc, if possible + * emptyreachable - recursively find all states reachable from s by EMPTY arcs + * + * The return value is the last such state found. Its tmp field links back + * to the next-to-last such state, and so on back to s, so that all these + * states can be located without searching the whole NFA. * - * Actually, as it stands this function always succeeds, but the return - * value is kept with an eye on possible future changes. + * The maximum recursion depth here is equal to the length of the longest + * loop-free chain of EMPTY arcs, which is surely no more than the size of + * the NFA, and in practice will be a lot less than that. */ -static int /* 0 couldn't, 1 could */ -unempty(struct nfa * nfa, - struct arc * a) -{ - struct state *from = a->from; - struct state *to = a->to; - int usefrom; /* work on from, as opposed to to? */ - - assert(a->type == EMPTY); - assert(from != nfa->pre && to != nfa->post); - - if (from == to) - { /* vacuous loop */ - freearc(nfa, a); - return 1; - } - - /* decide which end to work on */ - usefrom = 1; /* default: attack from */ - if (from->nouts > to->nins) - usefrom = 0; - else if (from->nouts == to->nins) - { - /* decide on secondary issue: move/copy fewest arcs */ - if (from->nins > to->nouts) - usefrom = 0; - } - - freearc(nfa, a); - if (usefrom) - { - if (from->nouts == 0) - { - /* was the state's only outarc */ - moveins(nfa, from, to); - freestate(nfa, from); - } - else - copyins(nfa, from, to); - } - else - { - if (to->nins == 0) - { - /* was the state's only inarc */ - moveouts(nfa, to, from); - freestate(nfa, to); - } - else - copyouts(nfa, to, from); - } - - return 1; +static struct state *emptyreachable(struct state *s, struct state *lastfound) { + struct arc *a; + + s->tmp = lastfound; + lastfound = s; + for (a = s->outs; a != NULL; a = a->outchain) { + if (a->type == EMPTY && a->to->tmp == NULL) + lastfound = emptyreachable(a->to, lastfound); + } + return lastfound; +} + +/* + * replaceempty - replace an EMPTY arc chain with some non-empty arcs + * + * The EMPTY arc(s) should be deleted later, but we can't do it here because + * they may still be needed to identify other arc chains during fixempties(). + */ +static void replaceempty(struct nfa *nfa, struct state *from, + struct state *to) { + int fromouts; + int toins; + + assert(from != to); + + /* + * Create replacement arcs that bypass the need for the EMPTY chain. We + * can do this either by pushing arcs forward (linking directly from + * "from"'s predecessors to "to") or by pulling them back (linking + * directly from "from" to "to"'s successors). In general, we choose + * whichever way creates greater fan-out or fan-in, so as to improve the + * odds of reducing the other state to zero in-arcs or out-arcs and + * thereby being able to delete it. However, if "from" is doomed (has no + * non-EMPTY out-arcs), we must keep it so, so always push forward in that + * case. + * + * The fan-out/fan-in comparison should count only non-EMPTY arcs. If + * "from" is doomed, we can skip counting "to"'s arcs, since we want to + * force taking the copyins path in that case. + */ + fromouts = nonemptyouts(from); + toins = (fromouts == 0) ? 1 : nonemptyins(to); + + if (fromouts > toins) { + copyouts(nfa, to, from, 0); + return; + } + + if (fromouts < toins) { + copyins(nfa, from, to, 0); + return; + } + + /* + * fromouts == toins. Decide on secondary issue: copy fewest arcs. + * + * Doesn't seem to be worth the trouble to exclude empties from these + * comparisons; that takes extra time and doesn't seem to improve the + * resulting graph much. + */ + if (from->nins > to->nouts) { + copyouts(nfa, to, from, 0); + return; + } else { + copyins(nfa, from, to, 0); + return; + } } /* * cleanup - clean up NFA after optimizations */ -static void -cleanup(struct nfa * nfa) -{ - struct state *s; - struct state *nexts; - int n; - - /* clear out unreachable or dead-end states */ - /* use pre to mark reachable, then post to mark can-reach-post */ - markreachable(nfa, nfa->pre, (struct state *) NULL, nfa->pre); - markcanreach(nfa, nfa->post, nfa->pre, nfa->post); - for (s = nfa->states; s != NULL; s = nexts) - { - nexts = s->next; - if (s->tmp != nfa->post && !s->flag) - dropstate(nfa, s); - } - assert(nfa->post->nins == 0 || nfa->post->tmp == nfa->post); - cleartraverse(nfa, nfa->pre); - assert(nfa->post->nins == 0 || nfa->post->tmp == NULL); - /* the nins==0 (final unreachable) case will be caught later */ - - /* renumber surviving states */ - n = 0; - for (s = nfa->states; s != NULL; s = s->next) - s->no = n++; - nfa->nstates = n; +static void cleanup(struct nfa *nfa) { + struct state *s; + struct state *nexts; + int n; + + /* clear out unreachable or dead-end states */ + /* use pre to mark reachable, then post to mark can-reach-post */ + markreachable(nfa, nfa->pre, (struct state *)NULL, nfa->pre); + markcanreach(nfa, nfa->post, nfa->pre, nfa->post); + for (s = nfa->states; s != NULL; s = nexts) { + nexts = s->next; + if (s->tmp != nfa->post && !s->flag) dropstate(nfa, s); + } + assert(nfa->post->nins == 0 || nfa->post->tmp == nfa->post); + cleartraverse(nfa, nfa->pre); + assert(nfa->post->nins == 0 || nfa->post->tmp == NULL); + /* the nins==0 (final unreachable) case will be caught later */ + + /* renumber surviving states */ + n = 0; + for (s = nfa->states; s != NULL; s = s->next) s->no = n++; + nfa->nstates = n; } /* * markreachable - recursive marking of reachable states */ -static void -markreachable(struct nfa * nfa, - struct state * s, - struct state * okay, /* consider only states with this mark */ - struct state * mark) /* the value to mark with */ +static void markreachable( + struct nfa *nfa, struct state *s, + struct state *okay, /* consider only states with this mark */ + struct state *mark) /* the value to mark with */ { - struct arc *a; + struct arc *a; - if (s->tmp != okay) - return; - s->tmp = mark; + if (s->tmp != okay) return; + s->tmp = mark; - for (a = s->outs; a != NULL; a = a->outchain) - markreachable(nfa, a->to, okay, mark); + for (a = s->outs; a != NULL; a = a->outchain) + markreachable(nfa, a->to, okay, mark); } /* * markcanreach - recursive marking of states which can reach here */ -static void -markcanreach(struct nfa * nfa, - struct state * s, - struct state * okay, /* consider only states with this mark */ - struct state * mark) /* the value to mark with */ +static void markcanreach( + struct nfa *nfa, struct state *s, + struct state *okay, /* consider only states with this mark */ + struct state *mark) /* the value to mark with */ { - struct arc *a; + struct arc *a; - if (s->tmp != okay) - return; - s->tmp = mark; + if (s->tmp != okay) return; + s->tmp = mark; - for (a = s->ins; a != NULL; a = a->inchain) - markcanreach(nfa, a->from, okay, mark); + for (a = s->ins; a != NULL; a = a->inchain) + markcanreach(nfa, a->from, okay, mark); } /* * analyze - ascertain potentially-useful facts about an optimized NFA */ -static long /* re_info bits to be ORed in */ -analyze(struct nfa * nfa) -{ - struct arc *a; - struct arc *aa; - - if (nfa->pre->outs == NULL) - return REG_UIMPOSSIBLE; - for (a = nfa->pre->outs; a != NULL; a = a->outchain) - for (aa = a->to->outs; aa != NULL; aa = aa->outchain) - if (aa->to == nfa->post) - return REG_UEMPTYMATCH; - return 0; +static long /* re_info bits to be ORed in */ +analyze(struct nfa *nfa) { + struct arc *a; + struct arc *aa; + + if (nfa->pre->outs == NULL) return REG_UIMPOSSIBLE; + for (a = nfa->pre->outs; a != NULL; a = a->outchain) + for (aa = a->to->outs; aa != NULL; aa = aa->outchain) + if (aa->to == nfa->post) return REG_UEMPTYMATCH; + return 0; } /* * compact - compact an NFA */ -static void -compact(struct nfa * nfa, - struct cnfa * cnfa) -{ - struct state *s; - struct arc *a; - size_t nstates; - size_t narcs; - struct carc *ca; - struct carc *first; - - assert(!NISERR()); - - nstates = 0; - narcs = 0; - for (s = nfa->states; s != NULL; s = s->next) - { - nstates++; - narcs += 1 + s->nouts + 1; - /* 1 as a fake for flags, nouts for arcs, 1 as endmarker */ - } - - cnfa->states = (struct carc **) MALLOC(nstates * sizeof(struct carc *)); - cnfa->arcs = (struct carc *) MALLOC(narcs * sizeof(struct carc)); - if (cnfa->states == NULL || cnfa->arcs == NULL) - { - if (cnfa->states != NULL) - FREE(cnfa->states); - if (cnfa->arcs != NULL) - FREE(cnfa->arcs); - NERR(REG_ESPACE); - return; - } - cnfa->nstates = nstates; - cnfa->pre = nfa->pre->no; - cnfa->post = nfa->post->no; - cnfa->bos[0] = nfa->bos[0]; - cnfa->bos[1] = nfa->bos[1]; - cnfa->eos[0] = nfa->eos[0]; - cnfa->eos[1] = nfa->eos[1]; - cnfa->ncolors = maxcolor(nfa->cm) + 1; - cnfa->flags = 0; - - ca = cnfa->arcs; - for (s = nfa->states; s != NULL; s = s->next) - { - assert((size_t) s->no < nstates); - cnfa->states[s->no] = ca; - ca->co = 0; /* clear and skip flags "arc" */ - ca++; - first = ca; - for (a = s->outs; a != NULL; a = a->outchain) - switch (a->type) - { - case PLAIN: - ca->co = a->co; - ca->to = a->to->no; - ca++; - break; - case LACON: - assert(s->no != cnfa->pre); - ca->co = (color) (cnfa->ncolors + a->co); - ca->to = a->to->no; - ca++; - cnfa->flags |= HASLACONS; - break; - default: - assert(NOTREACHED); - break; - } - carcsort(first, ca - 1); - ca->co = COLORLESS; - ca->to = 0; - ca++; - } - assert(ca == &cnfa->arcs[narcs]); - assert(cnfa->nstates != 0); - - /* mark no-progress states */ - for (a = nfa->pre->outs; a != NULL; a = a->outchain) - cnfa->states[a->to->no]->co = 1; - cnfa->states[nfa->pre->no]->co = 1; +static void compact(struct nfa *nfa, struct cnfa *cnfa) { + struct state *s; + struct arc *a; + size_t nstates; + size_t narcs; + struct carc *ca; + struct carc *first; + + assert(!NISERR()); + + nstates = 0; + narcs = 0; + for (s = nfa->states; s != NULL; s = s->next) { + nstates++; + narcs += 1 + s->nouts + 1; + /* 1 as a fake for flags, nouts for arcs, 1 as endmarker */ + } + + cnfa->states = (struct carc **)MALLOC(nstates * sizeof(struct carc *)); + cnfa->arcs = (struct carc *)MALLOC(narcs * sizeof(struct carc)); + if (cnfa->states == NULL || cnfa->arcs == NULL) { + if (cnfa->states != NULL) FREE(cnfa->states); + if (cnfa->arcs != NULL) FREE(cnfa->arcs); + NERR(REG_ESPACE); + return; + } + cnfa->nstates = nstates; + cnfa->pre = nfa->pre->no; + cnfa->post = nfa->post->no; + cnfa->bos[0] = nfa->bos[0]; + cnfa->bos[1] = nfa->bos[1]; + cnfa->eos[0] = nfa->eos[0]; + cnfa->eos[1] = nfa->eos[1]; + cnfa->ncolors = maxcolor(nfa->cm) + 1; + cnfa->flags = 0; + + ca = cnfa->arcs; + for (s = nfa->states; s != NULL; s = s->next) { + assert((size_t)s->no < nstates); + cnfa->states[s->no] = ca; + ca->co = 0; /* clear and skip flags "arc" */ + ca++; + first = ca; + for (a = s->outs; a != NULL; a = a->outchain) switch (a->type) { + case PLAIN: + ca->co = a->co; + ca->to = a->to->no; + ca++; + break; + case LACON: + assert(s->no != cnfa->pre); + ca->co = (color)(cnfa->ncolors + a->co); + ca->to = a->to->no; + ca++; + cnfa->flags |= HASLACONS; + break; + default: + assert(NOTREACHED); + break; + } + carcsort(first, ca - 1); + ca->co = COLORLESS; + ca->to = 0; + ca++; + } + assert(ca == &cnfa->arcs[narcs]); + assert(cnfa->nstates != 0); + + /* mark no-progress states */ + for (a = nfa->pre->outs; a != NULL; a = a->outchain) + cnfa->states[a->to->no]->co = 1; + cnfa->states[nfa->pre->no]->co = 1; } /* @@ -1402,260 +1334,199 @@ compact(struct nfa * nfa, * Really dumb algorithm, but if the list is long enough for that to matter, * you're in real trouble anyway. */ -static void -carcsort(struct carc * first, - struct carc * last) -{ - struct carc *p; - struct carc *q; - struct carc tmp; - - if (last - first <= 1) - return; - - for (p = first; p <= last; p++) - for (q = p; q <= last; q++) - if (p->co > q->co || - (p->co == q->co && p->to > q->to)) - { - assert(p != q); - tmp = *p; - *p = *q; - *q = tmp; - } +static void carcsort(struct carc *first, struct carc *last) { + struct carc *p; + struct carc *q; + struct carc tmp; + + if (last - first <= 1) return; + + for (p = first; p <= last; p++) + for (q = p; q <= last; q++) + if (p->co > q->co || (p->co == q->co && p->to > q->to)) { + assert(p != q); + tmp = *p; + *p = *q; + *q = tmp; + } } /* * freecnfa - free a compacted NFA */ -static void -freecnfa(struct cnfa * cnfa) -{ - assert(cnfa->nstates != 0); /* not empty already */ - cnfa->nstates = 0; - FREE(cnfa->states); - FREE(cnfa->arcs); +static void freecnfa(struct cnfa *cnfa) { + assert(cnfa->nstates != 0); /* not empty already */ + cnfa->nstates = 0; + FREE(cnfa->states); + FREE(cnfa->arcs); } /* * dumpnfa - dump an NFA in human-readable form */ -static void -dumpnfa(struct nfa * nfa, - FILE *f) -{ +static void dumpnfa(struct nfa *nfa, FILE *f) { #ifdef REG_DEBUG - struct state *s; - - fprintf(f, "pre %d, post %d", nfa->pre->no, nfa->post->no); - if (nfa->bos[0] != COLORLESS) - fprintf(f, ", bos [%ld]", (long) nfa->bos[0]); - if (nfa->bos[1] != COLORLESS) - fprintf(f, ", bol [%ld]", (long) nfa->bos[1]); - if (nfa->eos[0] != COLORLESS) - fprintf(f, ", eos [%ld]", (long) nfa->eos[0]); - if (nfa->eos[1] != COLORLESS) - fprintf(f, ", eol [%ld]", (long) nfa->eos[1]); - fprintf(f, "\n"); - for (s = nfa->states; s != NULL; s = s->next) - dumpstate(s, f); - if (nfa->parent == NULL) - dumpcolors(nfa->cm, f); - fflush(f); + struct state *s; + + fprintf(f, "pre %d, post %d", nfa->pre->no, nfa->post->no); + if (nfa->bos[0] != COLORLESS) fprintf(f, ", bos [%ld]", (long)nfa->bos[0]); + if (nfa->bos[1] != COLORLESS) fprintf(f, ", bol [%ld]", (long)nfa->bos[1]); + if (nfa->eos[0] != COLORLESS) fprintf(f, ", eos [%ld]", (long)nfa->eos[0]); + if (nfa->eos[1] != COLORLESS) fprintf(f, ", eol [%ld]", (long)nfa->eos[1]); + fprintf(f, "\n"); + for (s = nfa->states; s != NULL; s = s->next) dumpstate(s, f); + if (nfa->parent == NULL) dumpcolors(nfa->cm, f); + fflush(f); #endif } -#ifdef REG_DEBUG /* subordinates of dumpnfa */ +#ifdef REG_DEBUG /* subordinates of dumpnfa */ /* * dumpstate - dump an NFA state in human-readable form */ -static void -dumpstate(struct state * s, - FILE *f) -{ - struct arc *a; - - fprintf(f, "%d%s%c", s->no, (s->tmp != NULL) ? "T" : "", - (s->flag) ? s->flag : '.'); - if (s->prev != NULL && s->prev->next != s) - fprintf(f, "\tstate chain bad\n"); - if (s->nouts == 0) - fprintf(f, "\tno out arcs\n"); - else - dumparcs(s, f); - fflush(f); - for (a = s->ins; a != NULL; a = a->inchain) - { - if (a->to != s) - fprintf(f, "\tlink from %d to %d on %d's in-chain\n", - a->from->no, a->to->no, s->no); - } +static void dumpstate(struct state *s, FILE *f) { + struct arc *a; + + fprintf(f, "%d%s%c", s->no, (s->tmp != NULL) ? "T" : "", + (s->flag) ? s->flag : '.'); + if (s->prev != NULL && s->prev->next != s) fprintf(f, "\tstate chain bad\n"); + if (s->nouts == 0) + fprintf(f, "\tno out arcs\n"); + else + dumparcs(s, f); + fflush(f); + for (a = s->ins; a != NULL; a = a->inchain) { + if (a->to != s) + fprintf(f, "\tlink from %d to %d on %d's in-chain\n", a->from->no, + a->to->no, s->no); + } } /* * dumparcs - dump out-arcs in human-readable form */ -static void -dumparcs(struct state * s, - FILE *f) -{ - int pos; +static void dumparcs(struct state *s, FILE *f) { + int pos; - assert(s->nouts > 0); - /* printing arcs in reverse order is usually clearer */ - pos = dumprarcs(s->outs, s, f, 1); - if (pos != 1) - fprintf(f, "\n"); + assert(s->nouts > 0); + /* printing arcs in reverse order is usually clearer */ + pos = dumprarcs(s->outs, s, f, 1); + if (pos != 1) fprintf(f, "\n"); } /* * dumprarcs - dump remaining outarcs, recursively, in reverse order */ -static int /* resulting print position */ -dumprarcs(struct arc * a, - struct state * s, - FILE *f, - int pos) /* initial print position */ +static int /* resulting print position */ +dumprarcs(struct arc *a, struct state *s, FILE *f, + int pos) /* initial print position */ { - if (a->outchain != NULL) - pos = dumprarcs(a->outchain, s, f, pos); - dumparc(a, s, f); - if (pos == 5) - { - fprintf(f, "\n"); - pos = 1; - } - else - pos++; - return pos; + if (a->outchain != NULL) pos = dumprarcs(a->outchain, s, f, pos); + dumparc(a, s, f); + if (pos == 5) { + fprintf(f, "\n"); + pos = 1; + } else + pos++; + return pos; } /* * dumparc - dump one outarc in readable form, including prefixing tab */ -static void -dumparc(struct arc * a, - struct state * s, - FILE *f) -{ - struct arc *aa; - struct arcbatch *ab; - - fprintf(f, "\t"); - switch (a->type) - { - case PLAIN: - fprintf(f, "[%ld]", (long) a->co); - break; - case AHEAD: - fprintf(f, ">%ld>", (long) a->co); - break; - case BEHIND: - fprintf(f, "<%ld<", (long) a->co); - break; - case LACON: - fprintf(f, ":%ld:", (long) a->co); - break; - case '^': - case '$': - fprintf(f, "%c%d", a->type, (int) a->co); - break; - case EMPTY: - break; - default: - fprintf(f, "0x%x/0%lo", a->type, (long) a->co); - break; - } - if (a->from != s) - fprintf(f, "?%d?", a->from->no); - for (ab = &a->from->oas; ab != NULL; ab = ab->next) - { - for (aa = &ab->a[0]; aa < &ab->a[ABSIZE]; aa++) - if (aa == a) - break; /* NOTE BREAK OUT */ - if (aa < &ab->a[ABSIZE]) /* propagate break */ - break; /* NOTE BREAK OUT */ - } - if (ab == NULL) - fprintf(f, "?!?"); /* not in allocated space */ - fprintf(f, "->"); - if (a->to == NULL) - { - fprintf(f, "NULL"); - return; - } - fprintf(f, "%d", a->to->no); - for (aa = a->to->ins; aa != NULL; aa = aa->inchain) - if (aa == a) - break; /* NOTE BREAK OUT */ - if (aa == NULL) - fprintf(f, "?!?"); /* missing from in-chain */ +static void dumparc(struct arc *a, struct state *s, FILE *f) { + struct arc *aa; + struct arcbatch *ab; + + fprintf(f, "\t"); + switch (a->type) { + case PLAIN: + fprintf(f, "[%ld]", (long)a->co); + break; + case AHEAD: + fprintf(f, ">%ld>", (long)a->co); + break; + case BEHIND: + fprintf(f, "<%ld<", (long)a->co); + break; + case LACON: + fprintf(f, ":%ld:", (long)a->co); + break; + case '^': + case '$': + fprintf(f, "%c%d", a->type, (int)a->co); + break; + case EMPTY: + break; + default: + fprintf(f, "0x%x/0%lo", a->type, (long)a->co); + break; + } + if (a->from != s) fprintf(f, "?%d?", a->from->no); + for (ab = &a->from->oas; ab != NULL; ab = ab->next) { + for (aa = &ab->a[0]; aa < &ab->a[ABSIZE]; aa++) + if (aa == a) break; /* NOTE BREAK OUT */ + if (aa < &ab->a[ABSIZE]) /* propagate break */ + break; /* NOTE BREAK OUT */ + } + if (ab == NULL) fprintf(f, "?!?"); /* not in allocated space */ + fprintf(f, "->"); + if (a->to == NULL) { + fprintf(f, "NULL"); + return; + } + fprintf(f, "%d", a->to->no); + for (aa = a->to->ins; aa != NULL; aa = aa->inchain) + if (aa == a) break; /* NOTE BREAK OUT */ + if (aa == NULL) fprintf(f, "?!?"); /* missing from in-chain */ } -#endif /* REG_DEBUG */ +#endif /* REG_DEBUG */ /* * dumpcnfa - dump a compacted NFA in human-readable form */ #ifdef REG_DEBUG -static void -dumpcnfa(struct cnfa * cnfa, - FILE *f) -{ - int st; - - fprintf(f, "pre %d, post %d", cnfa->pre, cnfa->post); - if (cnfa->bos[0] != COLORLESS) - fprintf(f, ", bos [%ld]", (long) cnfa->bos[0]); - if (cnfa->bos[1] != COLORLESS) - fprintf(f, ", bol [%ld]", (long) cnfa->bos[1]); - if (cnfa->eos[0] != COLORLESS) - fprintf(f, ", eos [%ld]", (long) cnfa->eos[0]); - if (cnfa->eos[1] != COLORLESS) - fprintf(f, ", eol [%ld]", (long) cnfa->eos[1]); - if (cnfa->flags & HASLACONS) - fprintf(f, ", haslacons"); - fprintf(f, "\n"); - for (st = 0; st < cnfa->nstates; st++) - dumpcstate(st, cnfa->states[st], cnfa, f); - fflush(f); +static void dumpcnfa(struct cnfa *cnfa, FILE *f) { + int st; + + fprintf(f, "pre %d, post %d", cnfa->pre, cnfa->post); + if (cnfa->bos[0] != COLORLESS) fprintf(f, ", bos [%ld]", (long)cnfa->bos[0]); + if (cnfa->bos[1] != COLORLESS) fprintf(f, ", bol [%ld]", (long)cnfa->bos[1]); + if (cnfa->eos[0] != COLORLESS) fprintf(f, ", eos [%ld]", (long)cnfa->eos[0]); + if (cnfa->eos[1] != COLORLESS) fprintf(f, ", eol [%ld]", (long)cnfa->eos[1]); + if (cnfa->flags & HASLACONS) fprintf(f, ", haslacons"); + fprintf(f, "\n"); + for (st = 0; st < cnfa->nstates; st++) + dumpcstate(st, cnfa->states[st], cnfa, f); + fflush(f); } #endif -#ifdef REG_DEBUG /* subordinates of dumpcnfa */ +#ifdef REG_DEBUG /* subordinates of dumpcnfa */ /* * dumpcstate - dump a compacted-NFA state in human-readable form */ -static void -dumpcstate(int st, - struct carc * ca, - struct cnfa * cnfa, - FILE *f) -{ - int i; - int pos; - - fprintf(f, "%d%s", st, (ca[0].co) ? ":" : "."); - pos = 1; - for (i = 1; ca[i].co != COLORLESS; i++) - { - if (ca[i].co < cnfa->ncolors) - fprintf(f, "\t[%ld]->%d", (long) ca[i].co, ca[i].to); - else - fprintf(f, "\t:%ld:->%d", (long) ca[i].co - cnfa->ncolors, - ca[i].to); - if (pos == 5) - { - fprintf(f, "\n"); - pos = 1; - } - else - pos++; - } - if (i == 1 || pos != 1) - fprintf(f, "\n"); - fflush(f); +static void dumpcstate(int st, struct carc *ca, struct cnfa *cnfa, FILE *f) { + int i; + int pos; + + fprintf(f, "%d%s", st, (ca[0].co) ? ":" : "."); + pos = 1; + for (i = 1; ca[i].co != COLORLESS; i++) { + if (ca[i].co < cnfa->ncolors) + fprintf(f, "\t[%ld]->%d", (long)ca[i].co, ca[i].to); + else + fprintf(f, "\t:%ld:->%d", (long)ca[i].co - cnfa->ncolors, ca[i].to); + if (pos == 5) { + fprintf(f, "\n"); + pos = 1; + } else + pos++; + } + if (i == 1 || pos != 1) fprintf(f, "\n"); + fflush(f); } -#endif /* REG_DEBUG */ +#endif /* REG_DEBUG */ diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c index 35c4d99..aefd1ba 100644 --- a/src/backend/regex/regcomp.c +++ b/src/backend/regex/regcomp.c @@ -122,12 +122,15 @@ static void destroystate(struct nfa *, struct state *); static void newarc(struct nfa *, int, pcolor, struct state *, struct state *); static struct arc *allocarc(struct nfa *, struct state *); static void freearc(struct nfa *, struct arc *); +static int hasnonemptyout(struct state *); +static int nonemptyouts(struct state *); +static int nonemptyins(struct state *); static struct arc *findarc(struct state *, int, pcolor); static void cparc(struct nfa *, struct arc *, struct state *, struct state *); static void moveins(struct nfa *, struct state *, struct state *); -static void copyins(struct nfa *, struct state *, struct state *); +static void copyins(struct nfa *, struct state *, struct state *, int); static void moveouts(struct nfa *, struct state *, struct state *); -static void copyouts(struct nfa *, struct state *, struct state *); +static void copyouts(struct nfa *, struct state *, struct state *, int); static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int); static void delsub(struct nfa *, struct state *, struct state *); static void deltraverse(struct nfa *, struct state *, struct state *); @@ -146,7 +149,8 @@ static int push(struct nfa *, struct arc *); #define COMPATIBLE 3 /* compatible but not satisfied yet */ static int combine(struct arc *, struct arc *); static void fixempties(struct nfa *, FILE *); -static int unempty(struct nfa *, struct arc *); +static struct state *emptyreachable(struct state *, struct state *); +static void replaceempty(struct nfa *, struct state *, struct state *); static void cleanup(struct nfa *); static void markreachable(struct nfa *, struct state *, struct state *, struct state *); static void markcanreach(struct nfa *, struct state *, struct state *, struct state *); @@ -573,7 +577,7 @@ makesearch(struct vars * v, for (s = slist; s != NULL; s = s2) { s2 = newstate(nfa); - copyouts(nfa, s, s2); + copyouts(nfa, s, s2, 1); for (a = s->ins; a != NULL; a = b) { b = a->inchain;